Semiconductor devices with vertical transistor cells are based on control structures extending into a drift zone and adjoining semiconductor mesas that include the source and body zones of the transistor cells. In the on-state of the transistor cells, a high density charge carrier plasma in the drift zone ensures a low on-state resistance of the semiconductor device. Typically, thin semiconductor mesas or semiconductor mesas with constrictions reduce a leakage of charge carriers and keep the charge carrier plasma density high.
It is desirable to provide semiconductor devices with a low leakage of charge carriers from a charge carrier plasma in the on-state.